This invention relates to a toe ramp including forward and aft leaves adapted for use in various positions while carried by a ramp door to facilitate the loading and unloading of cargo into an aircraft; and more particularly, the present invention relates to an arrangement of parts for selectively positioning the aft leaf with respect to the forward leaf of the toe ramp into preselected positions whereby in one position the aft leaf is stowed beneath the forward leaf, in another position the aft leaf forms a truss supporting relationship with the ramp door for the forward leaf and in a third position the aft leaf forms an extension to the forward leaf.
As is known, aircraft currently in use are provided with toe ramps that are disconnected from the ramp doors of the aircraft during certain modes of cargo handling. The toe ramps are stored onboard the aircraft while loading operations are carried out with a K-type loader and during air-drop modes of operation. Large full-width toe ramps, such as provided on C-5 aircraft, require a powered and complex mechanism to disconnect and stow the toe ramp. The disconnect and stowing operations cannot be done quickly. Smaller toe ramps which are not full-width such as used on C-130 aircraft and C-141 aircraft, are disconnected and stowed manually. This is a cumbersome, time-consuming operation which usually requires the services of two men. Moreover, the smaller toe ramps must be adjusted laterally to accommodate tread widths of various different types of wheeled vehicles being loaded and unloaded.
The present invention is based on the realization that a toe ramp is necessary to provide an auxiliary bridge for certain loading and unloading modes on cargo aircraft having an aft loading ramp door. First, toe ramps are essential to passage of self-propelled, wheeled vehicles between the loading ramp and ground. Secondly, toe ramps are necessary for skidding or rolling cargo received or discharged at a fixed height, such as onto a flat-bed truck. Toe ramps are also necessary for rapid discharge of palletized cargo while the aircraft is taxiing such as during combat off-loading. While toe ramps are necessary during such loading and unloading modes, there are other instances wherein toe ramps are neither used nor needed during loading and unloading of cargo for aircraft. Toe ramps are not employed or needed for skidding or rolling cargo from adjustable-height vehicles, such as a military K-type loader and forklifts. Moreover, toe ramps are neither required nor needed for airdrop palletized cargo. In these instances, the toe ramp must be positioned or stowed in a manner so as to avoid creating obstacles that impede the efficient handling of cargo.
In addition to the foregoing, there are other important objectives by the military dealing with the design of a toe ramp. The toe ramp must be positioned by a single operator. The toe ramp must form a ground-to-ramp angle of 13.degree. or less. The toe ramp must be compatible with tread widths of all loadable vehicles and adapted for rapid conversion from an air-drop mode of operation to airland missions.